I point out, for illustration, the theory of dark matter/energy and string theory. Both of which have started out as hypothesis with few if any testable ways to observe them. At a Google tech talk Murray Gell-Mann, whose lab was where the idea of string theory arose, indicated that he was not very impressed with the idea and suggested it was completely untestable.

The challenge I see in God theory is that it is that people go off and start from some concept they learned in primary school and poke holes in that image. Rather than actually taking a scientific approach and asking what the nature of God might be, given the data they do have access to.

Note that this is completely distinct from theology, or the study of religions, rather it is an attempt at understanding God (which is often referred to as enlightenment).

As Dawkins and others have pointed out however, the God 'meme' has been used forever in human cultures to assert power over one group by another. Thus there is a lot of mental baggage around taking God seriously (think confirmational bias on steroids).

Example, I once talked to an engineer who would not even posit the existence of 'a' God because for them it meant there was a hell and they were afraid to think about what it would mean to spend eternity in such a place.

From that example you can see the confluence of what they were taught by a religion as a control mechanism (obey us or go to hell) versus his ability to ask critical questions. I suggested that a 'God' might exist and their might not be a hell. He found that pretty heretical but it gave him a way to ask the question without wincing.

My wonderings are around the source of sentience and the implementation of free will. Generally the debates of philosophers rather than scientists but one in which the presence of a 'God' (in the scientific sense) could be hypothsized as the difference between sentient and non-sentient. I thought it would be fun to write a short story where confirmational bias was the result of God knowing what you wanted the outcome of your experiment to be and making it so, leading too a lot of angels in therapy because they had made it work like you wanted and then you were all irritated that it wasn't reproducible or something.

Your approach could be used:

Now, God theories in general have multiple issues that make them unscientific. For example, if you claim that God is an entity that is 'beyond time', you need to define in scientific terms what it means to be beyond time.

Ok, so we'll put this 'God' entity thing in a dimension that is orthogonal to time like one of the 11 in string theory.

Another issue is that you would need to come up with some experiment that would prove that God does not exist.

You do have to work on some experiments, and being falsifiable is a slam dunk, but given that we're talking about something that has a will (or is will) its hard. I've often suggested that I can read the phone book for Perth Austrailia and see an indication that a Tom Smith exists, but if I can't get to Austrailia or contact it in anyway I'm hard pressed to prove he exists, even though he has a home address and everything. This is the current challenge with Dark Enery/Matter as well which is coming up with ways to actually see it. And we can't so we look for ways it would influence the stuff we can see. You can make the same argument for God, look for ways that if God exists things might be different. (caveat confirmational bias etc etc).

Even if you were to formulate a definition of God that would satisfy these requirements, it is doubtful that many believers would agree with that definition.

There is no rule that says for a theory to be legitimate it has to be believed by everyone :-) Many solid theories started out being believed by no one but the theorist themselves.

Thus, 'God theory' in general doesn't describe a scientific theory at all, and so it is fundamentally not related to science.

I don't think you succeed in your claim that God theories are 'unscientific'. I would agree with the claim if you said that some theories put forth about the nature of God are unscientific but that does not preclude the existence of a scientific theory about the nature of God.

To have a theory about God, you have to first accept, for the sake of argument, that God might exist. Then you can start looking ways to put boundaries around what God might or might not be, sort of like how collision analysis of partcles is telling us where the Higgs boson isn't. I caution you though, if you start looking for God you run the very real risk of being found.

I certainly agree with the skepticism in regards to some aspects of string theory, and my impression is that skepticism is widely held. However, I don't think your interpretation of the extra dimensions of string theory is correct when you suggest that it would be possible to insert a God into them. The extra dimensions of string theory are tiny and curled up, not additional time-dimensions.

The other major flaw that I see in your argument is that you don't define God. If you posit that God exists, you need to define what that means, and what that God is. I put it to you that any such definition you could come up with would render the concept of God mundane and not divine, and thus would be irrelevant to any believer. You are of course welcome to disprove me on that point.

My point is not that people need to believe in the conclusions of the theory or even the theory itself, but that people would disagree with your definition of God to such an extent to render any such theory meaningless.

edit: I should also say that it is absolutely true that any theory that cannot be disproven experimentally is not a valid scientific theory but merely a hypothesis. All of the examples you give are hypotheses that, at some point, either an experiment was conceived to test them, or that still remain hypotheses. This doesn't mean that untestable hypotheses are worthless, but they do not qualify as scientific theories (yet).

I see your point on the string theory, I was claiming that as long as you have an untestable hypothesis you can construct and arbitrary route to get there. So pre-supposing an additional dimension which is orthognal to space time, would create a space which existed in all time.

"The other major flaw that I see in your argument is that you don't define God."

That is intentional actually, it reflects the challenge that any two people have when they try to define God, as a species there is lots of variability there. But it does not preclude one from creating a definiton, and then creating an untestable hypothesis around that definition (which is the basis of my rebuttal)

One could define 'God' to be a system, mechanism, or phenomena that exists in a dimension orthogonal to space time which is aware of and can interact with beings and matter which exist in the space time that we inhabit. But your later comment is more on the mark.

"I put it to you that any such definition you could come up with would render the concept of God mundane and not divine, and thus would be irrelevant to any believer."

This speaks to the question of 'who cares'? Which is to say that you have to be very careful not to conflate what a religion defines as God (or a god in the case of multi-theism) vs a physics theory which is about the nature of something which could explain observed phenomena associated with 'God'.

In attempt to disentangle the two, consider that we don't have a physics theory of 'consciousness' either, although we have good information about brain chemistry and construction. We can show that 'something' is missing because its possible to create a nearly exact simulation of a brain's physical and chemical signalling makeup and such constructions do not demonstrate consciousness. Such experiments tend to disfavor hypothese which hold that consciousness is an emergent property of the brain's construction or composition.

And to be clear here it is not my intention to create an 'escape through rhetorical trickery' (as I was once accused by a dogmatic believer) rather I think about these things as a means of trying to understand or to quantify my own feelings and experiences.

You remark "My point is not that people need to believe in the conclusions of the theory or even the theory itself, but that people would disagree with your definition of God to such an extent to render any such theory meaningless." seems to imply that for a theory of God to be correct that other people would have to believe the theory and agree with the definition.

I don't think this prequisite holds.I think the only thing you need to have a solid theory is to be able to make predictions and a way to run experiments to test those predictions. So the cosmological theory of God would show how the phenomena labelled as 'God' can do what it does. And then there would a philosophical discussion about whether or not the 'entity' known as God is an emergent property of the mechanism or something else entirely.

I am strongly reminded of Marvin Minsky's lament about 'Artificial Intelligence' where the study of AI has been unfairly criticized for 'not making any progress.' In his report on the progress of AI [1] he says "Artificial Intelligence, as a field of inquiry has been passing through a crisis of identity. As we see it, the problem stems from the tendency for the pursuit of technical methods to become detached from their original goals so that they follow a developmental pattern of their own." He observes that once we know how to do something we just go off and do it and as an engineering exercise it no longer meets the more meta definition of 'Artificial Intelligence.'

So we have computers that play chess (which was once considered a strong indicator of artificial intelligence) and we dismiss it as directed graph analysis. Etc.

My point is that one can create a hypothesis about how God exists (one that satisfies popular properties of God like 'everywhere and everywhen at once') only to find that once its clear then its no longer 'divine or miraculous.' I was always amused by the ancient aliens hyphothesis (effectively a God theory in my mind) since if it was aliens doing things we already know how to do which were considered miracles by people who didn't know how to do them were we all duped?

Once you understand the physics of how God could exist then the question becomes one of motiviation and philosophy. This is why I carefully separate 'religion' which is a series of commandments which generally apply to 'believers' with built in penalties that apply to 'heathens' with the question of whether or not God might exist.

[1] http://web.media.mit.edu/~minsky/papers/PR1971.html